Distributed Quantum Dense Coding With Nonclassical Routing

Abstract

In entanglement-assisted communication theory, it is well-known that pre-shared entanglement between a sender and receiver facilitates decoding a maximum of two bits of information by sending just one qubit. This is commonly referred to as quantum dense coding. In the recent decade, several works have shown that using a control system to create additional resources like coherent control and indefinite causal order has provided advantages in communication protocols. Inspired by these, we propose a distributed dense coding protocol that uses a control system to superpose two dense coding processes, allowing us to simultaneously and coherently encode and non-classically route the sender's single-qubit system to two receiver labs. We find that dense coding with coherently controlled encoding and routing performs better than the standard dense coding protocol in both global and one-way LOCC decoding strategies employed by receiver labs in weak entanglement regimes and with noisy mixed states.